There is a long felt need for gelled products in the personal care market. Gels allow for application to the skin of cosmetically elegant materials that provide benefit to the skin.
One example of the use of gels is the jellification of cyclomethicone with a combination of water and water-soluble dimethicone copolyol materials. The gel is used to deliver antiperspirant actives to the skin in a dry feeling system. Typical of the technology is U.S. Pat. No. 5,623,017, issued Apr. 22, 1997 to Hill, entitled Clear silicone gels describes “a method of forming a thermodynamically stable transparent product by combining (i) water, (ii) a volatile cyclic methyl siloxane or volatile linear methyl siloxane; and (iii) a silicone polyether surfactant.” This patent exemplifies the approach that has been taken to make gels of cyclomethicone for use in personal care products. The patent is related to thickening cyclomethicone, not esters with water (which is absent in the present invention), with an ethoxylated silicone. In short the art teaches that there is a long felt need to make gels in the personal care industry.
Those materials that are clear in the solvent generally define the concept of what is soluble. Sodium chloride is soluble in water. That is it is clear, but is also uniformly distributed in the solution. Unlike sodium chloride, which makes a uniform concentration solvent, materials that are bipolar are clear in water, but do not have uniform distribution in the solvent. The common example is sodium lauryl sulfate (SLS). SLS has a water-soluble sulfate group and an oil soluble lauryl portion (C12 hydrophobe). When SLS is added to water it is clear and consequently soluble. However, the molecule accumulates at the surface, lowering the surface tension. At a concentration called the CMC (critical micelle concentration) agglomerates form. SLS has an oil soluble and water-soluble group as shown below:                CH3(CH2)11—SO4−Na+        Oil Soluble|Water soluble        
We have surprisingly found that in a way analogous to water based systems; ester based systems, into which alkyl silicones are introduced are soluble (form clear solutions) but at lower concentrations lower surface tension (from about 32 dynes/cm2 to 22 dynes/cm2) then above their cmc (critical micelle concentration) form micelles. In the past the phenomenon was thought to occur only in water based systems. The alkyl silicone is bipolar, (like SLS) but lacks a water-soluble group having instead an oil soluble alkyl group and an oil insoluble silicone group. Alkyl Silicones exist in two types as shown below:
Comb Products:
Terminal Products:

The selection of a proper alkyl silicone (that is one with a melting point of over 30° C., and combining it with specific liquid esters results in a gel that liquefies under pressure providing outstanding cosmetic aesthetics and delivery of a rande og oil soluble actives including sun screens.
By gel is meant a semi-solid material stabilized or set by a three-dimensional lattice system. Because one additive has a bipolar amphilic structure the molecules accumulate preferentially at the interface of two immiscible phases. If the concentration at the interface exceeds the critical micelle forming concentration (cmc), a colloidal surfactant solution is produced. With increasing concentration, or volume fraction of the internal phase, such a solution becomes a structured gel.
Bailey in U.S. Pat. No. 3,299,112 describes products formed from a ternary system of water, a silicone oil, and a silicone polyether. But in contrast to my invention, the products in Bailey are emulsions which are not clear; the ternary system in the '112 patent is not a gel; the silicone oil in Bailey is not a volatile cyclic VMS; and where Bailey does describe a linear silicone oil, it is not a volatile linear silicone oil.
The structured gels of the present invention are oil soluble esters that are modified to have unique skin spreadability properties. This provides particular value in the personal care arena. Specifically, the ester based structured gels are useful as a carrier in antiperspirants, pigmented products, skin care products, and the like since they spread rapidly and efficiently on the skin from a stiff gel providing emmoliency and a host of ester soluble additives including sun screen actives, hydroxy acids, antioxidants, flavonoids, tocopherol, vitamins and the like. The gels are very cosmetically appealing having a dry feel on the skin and provide a lubricious property which improve the properties of skin creams, skin care lotions, moisturizers, facial treatments such as acne or wrinkle removers, personal and facial cleansers, liquid soaps, bath oils, perfumes, colognes, sachets, sunscreens, pre-shave and after-shave lotions, shaving soaps, and shaving lathers. It can be used in hair shampoos, hair conditioners, hair sprays, mousses, permanents, depilatories, and cuticle coats, to enhance cosmetic elegance.
In cosmetics, the compositions of the present invention will function as a leveling and spreading agent for pigments in make-ups, color cosmetics, foundations, blushes, lipsticks, lip balms, eyeliners, mascaras, oil removers, color cosmetic removers, and powders. It is also useful as a delivery system for oil and water-soluble substances such as vitamins. When incorporated into sticks, other gels, lotions, aerosols, and roll-ons, the compositions of the present invention impart a silky-smooth feeling, an outstanding payout.